Fluorescent lighting system with reflectors for eliminating end shadows



Oct. 20, 1970 E. A. FENNER 3,535,505

FLUORESCENT LIGHTING SYSTEM WITH REFLECTORS FOR ELIMINATING END SHADOWS Filed March 14, 1968 5 Sheets-Sheet 1 k4? I fun/x7. Fen/ref 4770A Mag-r IA/VEIVTOL" Oct. 20, 1970 E. A. FENNER I 3,535,505

FLUORESCENT LIGHTING SYSTEM WITH REFLECTORS FOR ELIMINATING END SHADOWS Filed March 14, 1968 5 Sheets-Sheet 2 lA/Vf/VTOK 6rrrer/ I. Fen/fer E. A. FENNER Oct. 20, 1970 SYSTEM WITH REFLECTORS F0 FLUORESCENT LIGHTING ELIMINATING END SHADOWS 5 Sheets-Sheet 5 Filed March 14, 1968 N L 7 L frmer/ A Fen/rel United States Patent 013 ice 3,535,505 FLUORESCENT LIGHTING SYSTEM WITH REFLECTORS FOR ELllVIINATING END SHADOWS Ernest A. Fennel, Anaheim, Calif., assignor to Bruce Industries, Inc., Gardena, Caliti, a corporation of California Filed Mar. 14, 1968, Ser. No. 713,137 Int. Cl. B60q 3/02 US. Cl. 240-735 13 Claims ABSTRACT OF THE DISCLOSURE The lighting system includes elongated lamps arranged in end-to-end relationship and partially surrounded by elongated reflector means for directing the illumination from the lamps laterally outwardly thereof. Spread light reflectors, one of which is positioned adjacent each end of the lamps, collect light from the adjacent lamp and focus such collected light laterally outwardly of the lamp to thereby provide even illumination along the entire length of the row of lamps. The reflective surface of each spread light reflector is concave both in an axially extend ing plane and in a transverse plane.

BACKGROUND OF INVENTION Many indirect lighting systems use elongated fluorescent lamps arranged in end-to-end relationship. Cove lighting systems such as are used in some large modern passenger aircraft are exemplary of lighting systems of this type.

When fluorescent lamps are arranged in end-to-end relationship, the illumination therefrom travels laterally outwardly and leaves a dark region laterally outwardly of the zone between the ends of the adjacent lamps. As the end of the lamps have sockets thereon, which do not form a part of the lighting portion of the lamp, this dark region cannot be eliminated even if the ends of the lamps are placed in abutting relationship. Furthermore, for aircraft lighting systems, it is desired to use as few lamps as possible to minimize the weight penalty introduced by the aircraft lighting system. Therefore, placement of the lamps in abutting relationship is not desirable.

The lamps can be overlapped to eliminate the dark region; however, this tends to introduce hot spots into the lighting pattern and does not produce a lighting pattern of even intensity. Furthermore, overlapping of the lamps is not desirable for aircraft lighting systems because of the weight of the additional lamps.

Several reflector systems have also been proposed in an attempt to eliminate the dark spots between adjacent lamps. The reflector systems used heretofore have been inadequate in that the dark spots, hot spots and shadows are produced in varying degrees.

SUMMARY OF THE INVENTION The present invention provides a reflector system which eliminates the dark spots between adjacent lamps and does so without casting objectionable shadows or hot spots. Thus, even illumination is provided along the entire row of lamps and no dark region is evident intermediate adjacent lamps.

The present invention teaches that illumination of even intensity can be provided by using a reflector system including an elongated reflector and several spread light reflectors. The elongated reflector partially surrounds the lamps which are arranged in end-to-end relationship and directs the illumination therefrom laterally outwardly. The elongated reflector directs light from the lighting portion, i.e. the portion of the lamp from which light is Patented Oct. 20, 1970 emitted, laterally outwardly and therefore leaves a dark region or shadow laterally outwardly of the zone between the ends of adjacent lamps.

To eliminate this dark region, the present invention provides a spread light reflector for collecting light from a diffuse source such as the elongated lamp and focusing such collected light on a region laterally outwardly of the zone intermediate adjacent lamps. The preferred form of spread light reffector disclosed herein is difficult to precisely describe and can only be fully described with reference to the accompanying drawings. However, in connection with spread light reflectors, the present invention provides several concepts each of which individually contributes to the advantageous results obtainable with the present invention.

Thus, the present invention teaches that the spread light reflector should have a reflecting surface which is concave in two directions and opens generally toward the lamp. Preferably, the reflecting surface is concave in a longitudinal directon and in a direction transverse thereto. This is necessary to allow gathering of the light from the diffuse fluorescent lamp source and focusing such collected light laterally outwardly into the region laterally outwardly of the zone intermediate adjacent lamps.

The present invention also teaches that the spread light reflector should be positioned adjacent one end of the lighting portion of the lamp. Preferably, a spread light reflector is positioned at each end of each of the lighting portion of each of the lamps. The precise position of the spread light reflector for a particular lighting requirement can only be determined experimentally by positioning the reflector at diflerent angles and locations until it projects the desired pattern and intensity of light, However, to project light into the dark region laterally outwardly of the space between adjacent lamps in the most advantageous fashion, one end of the elongated reflector should be positioned laterally outwardly of an end of the lighting portion while the other end of the reflecting surfaces should be positioned axially outwardly and laterally of said end of the lighting portion. By positioning the spread light reflectors in this manner, the lamps can be spaced substantially to thereby further reduce the weight and power requirements of the lighting system.

To permit further increasing the spacing between adjacent lamps, each of the spread light reflectors is preferably elongated in the direction of elongation of the lamps. However, if the system is used where the lamps my be spaced relatively close together, the degree of elongation may be reduced or eliminated.

To further improve the quality and evenness of the illumination, the spread light reflector should have a generally spherical portion and a generally parabolic portion with the spherical portion being positioned generally laterally outwardly of the illuminating portion of the lamp and with the parabolic portion preferably being spaced axially outwardly, at least in part, from the lighting portion of the lamp. In addition, the portion of the reflecting surface spaced axially outwardly from the lighting portion of the lamp should be preferably at least slightly wider than the region of the reflecting surface spaced laterally of the lighting portion. If this condition were reversed, there would be a hot spot directly over the end of the lamp.

The reflecting surface of the spread light reflector is preferably specular in order that the light collected thereby can be properly focused in the region desired. The reflecting surface of the elongated reflector can be either specular or diffuse over a major portion thereof, but for optimum results, the portions of the reflecting surface of the elongated reflector immediately adjacent the spread light reflectors should be diffuse. If both, the spread light reflector and the elongated reflector were specular in this region, the edge of the spread light reflector would project a shadow onto the wall region. Thus, to avoid this shadow, the elongated reflector is preferably diffuse immediately adjacent the spread light reflector.

To further reduce the weight of the lighting system, the spread light reflectors are preferably constructed of lightweight sheet-like material.

Various other concepts and parameters of the lighting system and of the spread light reflector are pointed out in connection with the description of the preferred exemplary embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a transverse sectional view through an indirect lighting system installed in an airplane.

FIG. 2 is a top plan view of a typical spread light reflector with the concave reflecting surface thereof facing upwardly.

FIG. 3 is a front elevational view of the spread light reflector.

FIGS. 4A-4I are inverted sectional views taken along lines A-I respectively of FIG. 2 and illustrating the shape of the spread light reflector at various areas therealong.

FIG. 5 is a transverse sectional view similar to FIG. 1 but on an enlarged scale, illustrating some of the details of the lighting system.

FIG. 6 is a fragmentary view of the lighting system taken along line 6-6 in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, FIG. 1 illustrates a lighting system 11 constructed in accordance with the teachings of this invention and mounted in an aircraft 13. Although the lighting system 11 is particularly adapted for use in an airplane, it may also be used in other environments. The aircraft 13 may be of any type in which indirect lighting along the wall thereof is desirable. The aircraft 13 includes a wall 15 on which a passenger service unit 17 is mounted and projects laterally into the interior of the cabin of the aircraft.

The lighting system 11 is mounted on the upper surface of the passenger service unit 17 and beneath a ceiling 19 of the cabin. It is important that the lighting system 11 be mounted on the passenger service unit 17 beneath a line of sight 21. All equipment positioned on the passenger service unit 17 and located below the line of sight 21 is assumed to be not visible to the passenger in the aircraft. The lighting system 11 is provided for purposes of indirectly illuminating a region 23 of the wall 15 beginning at or below the point where the line of sight 21 intersects the wall 15 and extending upwardly therefrom any desired amount. If desired, the system 11 may also illuminate a portion of the ceiling 19.

Referring to FIGS. 5 and 6, it can be seen that the lighting system 11 generally includes a plurality of elongated lamps 25 arranged in end-to-end relationship, an elongated reflector 27, and several spread light reflectors 29. The lamps 25 can be mounted in any suitable fashion as by mounting brackets 31 which in turn may be secured to the elongated reflector 27. Each of the lamps 25 may also be supported intermediate the mounting brackets 31 by a center support 32, which may also be suitably mounted on the elongated reflector 27. Each of the lamps 25 has a socket 33 at each end thereof from which no light is emitted and the portion of the lamp 25 intermediate the sockets 33 defines a lighting portion 35 of the lamp. The lamps 25 are mounted in spaced axial relationship with the confronting sockets 33 thereof being spaced to reduce the total number of lamps required.

The elongated reflector 27 may extend continuously for the full length of the lighting system or may be interrupted, if desired, adjacent the ends of each of the lamps 25 to provide space for mounting of the reflectors 29. In the embodiment illustrated, the elongated reflector 27 is provided in a plurality of axially spaced sections with the reflectors 29 being mounted therebetween as shown in FIGS. 5 and 6. As best seen in FIG. 5, the elongated reflector 27 includes two reflecting members 37 and 39. The reflecting member 37 partially surrounds the lamp 25 and has a web portion 41 resting on the upper surface of the passenger sevice unit 17 and suitably rigidly aflixed thereto. The reflecting member 37 also has a mounting bracket portion 43 which extends upwardly from the web portion 41 and is rigidly aflixed to the reflecting member 39 to thereby rigidly interconnect the two reflecting members. The reflecting member 37 has an overhanging ledge portion 45 above the lamp 25 which prevents the illumination from the lamp 25 from striking the region 23 of the wall 15 appreciably below the point at which the line of sight 21 intersects the region 23.

The elongated reflector 27 was formed from a member of generally parabolic cross section and the axis of the lamp is placed along the focal line of the parabolic member. The parabolic member was bent or shaped to form the various flat and curved regions shown in FIG. 5.

The reflecting portion 39, in the embodiment illustrated, is curved and preferably generally cylindrical. The elongated reflector 27 is concave in transverse cross section and defines an elongated slot 46, which at least partially forces the region 23. The reflecting portion 39 receives light directly from the lamp 45 as well as light which is reflected thereto by the reflecting member 37 and reflects it upwardly through the slot 46 and onto the region 23 of the wall 15. The effect of the elongated reflector 27 is to illuminate the region 23 at all areas therealong except portions of the region 23 lying laterally outwardly of the space between adjacent lamps. The regions of the elongated reflector 27 which lie immediately adjacent the spread light reflectors 29 are diffuse and the regions lying directly laterally outwardly of the lighting portions 35 of the lamps 25 are preferably specular.

The spread light reflectors 29 serve to illuminate the portions of the region 23 which lie laterally outwardly of the region between adjacent lighting portions 35- of the lamps. A preferred form of the reflector 29 is shown quite accurately as to shape in FIGS. 24, while the illustrations of the reflector 29 in FIGS. 1, 5 and 6, are generally dia grammatic. The spread light reflector 29 is preferably constructed of thin sheet-like material such as aluminum and has an elongated reflecting surface 47 which is preferably completely specular.

The spread light reflector 29 is in the form of a shallow basin which is concave in a plane extending longitudinally of the lamps 25 and in a plane extending generally transverse thereto. The reflector 29 has a relatively wide end portion 51 and a relatively narrow end portion 53. The reflecting surface 47 is preferably generally spherical from section line E (FIG. 2) to the left end (FIG. 2) of the reflector and is generally parabolic from the section line E to the righthand end of the reflector.

FIG. 4 shows several sectional views of the reflector 29. FIGS. 4A through 4B show generally spherical sections and FIGS. 4F through 41 show generally parabolic sections.

In actual use of the reflector, the concave portion is directed generally toward the lamps 25 so that the concave portion performs the light collecting and reflecting func tion. As shown in FIG. 6, one of the spread light reflectors 29 is positioned adjacent each end of the lamps 25, and more specifically, one of the spread light reflectors is positioned adjacent each end portion of the lighting portions 35. The spreadlight reflectors may be suitably mounted directly to the elongated reflector 27 by an integral apertured bracket portion 49. Preferably the wide end 51 lies generally axially outwardly of the lighting portion 35 while the narrow portion 53 lies generally laterally of the lighting portion.

For optimum results in the embodiment illustrated, the longitudinal axis of the spread light reflector 29 is preferably generally parallel to the longitudinal axis of the lamp 25. In the embodiment illustrated, the end of the lighting portion 35 terminates at the midpoint of the longitudinal dimension of the spread light reflector 29. Also, the spread light reflector 29, in the embodiment illustrated, is positioned toward the interior of the airplane from the lamp 25 and is turned upwardly as shown in FIG. so that it will reflect light from the lamp 25 onto the region 23 of the wall- 15. The particular angle at which the spread light reflector 29 extends upwardly can be varied depending upon the desired position for the reflected light on the region 23. In any event, it is generally desirable to position the spread light reflector 29 laterally of the lamp 25 and on the inboard side thereof with the reflector projecting upwardly to reflect the beam of light at the desired location of the region 23.

The spread light reflector 29 illustrated in FIGS. 24 is a righthand unit, i.e. a unit which is used at the right end of each of the lamps 25 as viewed in FIG. 6. Lefthand units, which are the mirror image of the reflector shown in FIGS. 24 should be employed for the lefthand end of the lamps 25 as viewed in FIG. 6.

Although the form of spread light reflector illustrated in FIGS. 2-4 is the preferred form, it should be understood that the spread light reflector may assume different shapes in accordance with the various concepts of the present invention outlined herein. That is, the precise shape, size and position of the reflectors 27 and 29 relative to the lamp 25 can be varied to suit diflerent environments and different lighting requirements.

By way of illustration, the angle of the spread light reflector 29 relative to the lamps 25 can be varied to change the position of the beam light reflected thereby onto the region 23. The degree of overhang of the overhanging ledge 45 can be varied to change the elevation of the lowermost portion of the light provided by the systemv 11. The shape of the reflector 27 can be varied to cause a light to be projected therefrom along a different zone. Although exemplary embodiments of the invention have been shown and described, many changes, modifications, and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

I claim: 1. In a lighting system, the combination of: first and second elongated lamps, each of said lamps having a lighting portion from which illumination can be emitted, each of said lighting portions having an end;

means for mounting said lamps with said ends of said lighting portions thereof being adjacent and with the lighting portion of said first lamp being spaced from the lighting portion of said second lamp, illumination from both of said lamps extending laterally outwardly thereof to leave a relatively dark region laterally outwardly of the region between the spaced lighting portions; and

spread light reflector means for gathering light from at least one of said lighting portions of said lamps and directing it toward said relatively dark region to illuminate same, said spread light reflector means including a spread light reflector having a reflective surface and mounted with a first region of the re flective surface laterally outwardly of said end of said lighting portion of said first lamp and with a second region of the reflective surface being intermediate said lighting portions, said reflective surface being concave in a direction generally parallel to the first lamp and in a direction generally transverse thereto.

2. A combination as defined in claim 1 wherein said reflective surface is specular.

3. A combination as defined in claim 1 wherein said regions of said reflective surface are contiguous and spread light reflectors at least along said reflective surface is incapable of passing light.

4. In a lighting system, the combination of:

first and second elongated lamps, each of said lamps having an end and a lighting portion from which illumination can be emitted;

means for mounting said lamps with said ends thereof being adjacent and with the lighting portion of said first lamp being spaced from the lighting portion of said second lamp;

elongated reflector means extending along said first and second elongated lamps for directing the illumination from said lamps laterally outwardly of the lamps to leave a relatively dark region laterally outwardly of the area between the spaced lighting portions;

first and second spread light reflector means mounted adjacent the ends of said first and second lamps, respectively, for gathering light from their respective lamps and directing it into the relatively dark region; and

each of said spread light reflectors having a reflective surface which is concave in an axially extending plane and in a transverse plane, said reflective surface generally facing its respective lamp and having a first region positioned generally laterally outwardly of an end portion of its respective lighting portion and a second region contiguous said first region and positioned generally axially outwardly and laterally of said end portion of its respective lighting portion.

5. A combination as defined in claim 4 wherein said elongated reflector means extends along a major portion of said lamps and at least substantially continuously between said ends of said lamps, and said first and second spread light reflector means are mounted at least partially within said elongated reflector means.

6. A combination as defined in claim '4 wherein the portion of the elongated reflector means adjacent the spread light reflectors are diffuse.

7. In a lighting system, the combination of:

an elongated lamp having a lighting portion from which illumination can be emitted, said lighting portion having end portions;

means for mounting said lamp to permit illumination from said lighting portion to be directed laterally therefrom;

a spread light reflector for gathering light from the lighting portion of the lamp and focusing it at an area spaced from the lamp, said spread light reflector having a reflective surface facing said lamp and defining a shallow concavity opening generally in the direction of said lamp, said reflective surface being concave in a direction generally parallel to the lamp and in a direction generally transverse thereto;

said spread light reflector being mounted with a first region of the reflective surface being positioned laterally outwardly of one end portion of the lighting portion of the lamp and with a second region of the reflective surface being spaced generally axially and laterally of said one end portion of the lighting portion of the lamp; and

said first region of said reflective surface being generally cylindrical and said second region of said reflective surface being generally parabolic.

8. In a lighting system, the combination of:

first and second elongated lamps, each of said lamps having an end and a lighting portion from which illumination can be emitted;

means for mounting said lamps with said ends thereof being adjacent and with the lighting portion of said first lamp being spaced from the lighting portion of said second lamp;

elongated reflector means extending along said first and second elongated lamps for directing the illumination from said lamps laterally outwardly of the lamps to leave a relatively dark region laterally outwardly of the area between the spaced lighting portions;

first and second spread light reflector means mounted adjacent the ends of said first and second lamps, respectively, for gathering light from their respective lamps and directing it into the relatively dark region; and

each of said spread light reflectors having a reflective surface which is concave in an axially extending plane and in a transverse plane, said reflective surface generally facing its respective lamp and having a first region positioned generally laterally outwardly of an end portion of its respective lighting portion and a second region positioned generally axially outwardly and laterally of said end portion of its respective lighting portion, said second region of said reflective surface being generally parabolic and wider than said first region of said reflective surface, said first region of said reflective surface being generally spherical, and said spread light reflector being elongated in generally the same direction as the lamps.

9. A lighting system comprising:

an elongated lamp having a lighting portion from which illumination can be emitted, said lighting portion having end portions;

means for mounting said lamp to permit illumination from said lighting portion to be directed laterally therefrom;

a spread light reflector having a shallow concavity opening generally in the direction of said lamp, the surface of said concavity being reflective, said reflective surface and said concavity being concave in a direction generally parallel to the lamp and in a direction generally transverse thereto; and

said spread light reflector being mounted with a first region of the reflective surface being positioned laterally outwardly of one end portion of the lighting portion of the lamp and with a second region of the reflective surface being spaced generally axially outwardly and laterally of said one end portion of the lighting portion of the lamp, said reflective surface of the spread light reflector reflecting at least some of the light from the lighting portion of the lamp to an area spaced axially outwardly and laterally of the lighting portion.

10. A combination as defined in claim 9 wherein said spread light reflector is elongated in generally the same direction as the lamp.

11. A combination as defined in claim 9 wherein said first region of said reflective surface is narrower in a plane transverse to the lamp than said second region of said reflective surface.

12. A lighting system as defined in claim 9 wherein said spread light reflector is opaque.

13. A lighting system as defined in claim 9 wherein said reflective surface extends continuously over the concavity and the concavity extends less than around the lighting portion of the lamp.

References Cited UNITED STATES PATENTS 2,434,951 1/1948 Netting 24051.11 3,202,814 8/1965 Ceglia 2409 NORTON ANSHER, Primary Examiner K. C. HUTCHISON, Assistant Examiner US. Cl. X.R. 

